Method of treating impregnated fabrics



vthrough the saturant be raised in the passage of the saturated felt Patented Aug. 9, 1932 UNITED STATES PATENT OFFICE HAROLD 1. HAYDEN, OF WOODBRIDGE, NEW JERSEY, ASSIGNOB TO THE BARBER ASPHALT COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF WEST VIRGINIA No Drawing.

My invention relates to a method for treating impregnated fabrics, as, for example, felt, or other fabric, paper and the like, saturated with, for example, bitumen, as asphalt, fill; with rubber, casein, drying oils and the Heretofore it has been known to saturate, for example, felt with bitumen, as asphalt, or the like, the saturated felt being, for example, utilized as a base for various products, as roofing, floor covering, etc. In the preparation of saturated felt, the felt is customar-' ily passed through a bath of saturant, as, for example, asphalt heated to produce the requisite fluidity to enable it to penetrate the felt, then rolled in large rolls wherein the heat is retained enabling completion of the penetration of the asphalt, and finally the saturated felt is rolled in the usual commercial size roll.

While saturated fabric, such as felt, as heretofore produced, is satisfactory for many purposes, it is possessed of a certain irregularity of surface, due principally to the pres ence of protruding fibres, or groups of fibres, which whether or not present before saturation will be, as it were, raised upin the course of treatment to effect saturation, and to the presence of areas of non-uniform saturation of the fabric. For example, felt usually contains moisturewhich is released by the hot saturant and escapes in the form of vapor which in escaping raises fibres on the surface of the felt. Further, fibres are raised on the surface by the bending of the felt back and forth about small rolls in passing it and fibres are likely to through squeeze rolls for the removal of excess saturant.

Such irregularity of surface is highly disadvantageous where the saturated fabric is used, for example, as a base for a floor covering, in the production of which the saturant is customarily sealed in with a paint coat or coats, since t e protruding fibres will extend through the paint coats, or the paint will aggregate about such fibres or groups of fibres, andthe paint coats will be non-uniform over areas of non-uniform saturation.

Now in accordance with my invention, I so ,bituminously saturated felt,

lated speed METHOD OF TREATING IMPREGNATED FABRICS Application filed November 10, 1928. Serial No. 318,602;

treat saturated fabric and more particularly bituminous saturated felt, as to eflect the elimination of surface irregularities and of protruding fibres, or groups of fibres, and at the same time so as to promote the elimination of areas of non-uniform saturation and tend to smooth the surface.

In accordance with my invention, for example, .as applied to the treatment of I first effect the desired saturation of a felt of desired composition in the usual manner, as for example, by passing the felt, in a strip, through a bath of, for example, asphalt heated to render it desirably fluid. left the bath, I subject a surface, or both surfaces, thereof to the action of heat, as a flame, radiant heat, an incandescent wire, a heated metal shoe, or the like, at such temperature and for such period of time as will effect combustion of protruding fibres. For example, the felt, in a strip, may be passed at a reguover, or in contact with, a suitable source of heat as, for example, a flame, from a burner extending transversely of the direction of travel of the strip, or between flames from apair of burners where both surfaces of the felt are to be treated, the flame, or flames, or other source of heat, being at a temperature at which the fibres will be burned off in the travel of the strip without combustion of the saturant.

As the surface of the saturated felt comes into the influence of the heat of, for example, a flame, any protruding fibres, or groups of fibres, will be burned off. The heat will tend to maintain the temperature of the saturant and hence its fluidity, thus permitting its more complete and more uniformipenetration and, at the same time, will enable the saturant adjacent the surface of the felt to smooth out due to the retention of its fluidity for an increased period after removal of the felt from the body of saturant in the bath and after elimination of protruding fibres. As a result of the treatment of saturated fabric in accordance with my invention, the

fabric will be found to have a relatively smoother surface, free from irregularities After the saturatedfelt has Y fibres, and at the same time the fabric will be found to have an increased uniformity of saturation throughout.

Saturated fabric treated in accordance with my invention will be found to lend its 31f 'to any use and to lend itself more particularly to use as a base for floor coverings, where smoothness of surface and absenceof protrading fibres are essential characteristics for the effective application and maintenance of sealing and decorating coats. a

' It will be understood that in carrying out my invention there is not required any special form of apparatus, it being obvious that any means for applyin heat suflicient to remove protrudin fibres rom the surface, or surfaces, of t e fabric will be effective, though for its application on a commercial scale apparatus for passin the fabric in a strip over a suitable source 0 heat will be desirable. It will be further understood that while I have illustrated the ap lication of my methol more particularly to ituminously impregnated felt, it is applicable to saturated fabrics other than felt and to fabrics saturated with substances other than bitumen and which will not present an undue fire hazard when subjected to the treatment.

It will be understood that while, in carrying out my invention, a flame will afford a desirable source of heat, I contemplate the use of radiant heat, an incandescent wire, a heated metal shoe or other suitable source of heat as equivalent to a flame.

Having now fully described my invention,

what I claim and desire to protect by Letters Patent is:

1. The method of producing a bituminously saturated fabric which includes passing a strip of fabric into a bath of bitumen heated to render it fluid, withdrawing the strip from the bath, and before the bitumen has cooled subjecting a surface of the strip to the action of a flame at a temperature and for a period of time sufiicient to permit fibres protruding from the surface to be burned off.

2, The method of producing a bituminously saturated fabric which includes passing a strip of fabric into a bath of asphalt heated to render it fluid, withdrawing the strip from the bath and while the asphalt retains substantially its fluidity subjecting a surface of the strip to the action of a flame at a temperature and for a period of time suflicient to permlt fibres protrudlng from the surface to be burned off.

In testimony of which invention I have hereunto set my hand on this' 3rd day of November, 1928.

. HAROLD P. HAYDEN. 

